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Doc.-no.: DPC310_01_EN Issue: 01/2018
5.3 Threshold calculation
Exampel: Threshold calculation
The set limit value must be between minimum and maximum flow.
As reference device we choose DPC310 with a measuring range of 0...1000 Pa.
The limit value calculation formula:
V = √ΔP × k
Given values:
Measuring range =
0...1000 Pa
; k-Factor (k) =
116
; Limit value (V) =
1200m
3
/h
It follows:
ΔP= (V / k)
2
= (1200 / 116)
2
=
107 Pa > 20 Pa = 2% of the measuring range
Minimal flow:
V_min = √(0,02 x 1000) x 116 = 519 m
3
/h
Maximal flow:
V_max = √(1000) x 116 = 3668 m
3
/h
Result:
The limit value of
1200 m
3
/h
is between V_min and V_max and adjustable by
our
DPC310 (0...1000 Pa)
.
5.4 Function alarm output
The DPC310 has an open collector alarm output (terminal 7+ 8-); depending on the op-
erating mode the function ist different.
When an alarm occurs, an exclamation mark (!) indicates the alarm state (2nd
line / 16th character).
The open collector output has two different states:
High resistive to disable an external circuit
Low resistance, to connect an external circuit with maximum load of 30 Vdc / 30 mA
5.4.1 Control mode:
In order to recognize the limits of control, the alarm output in control mode refers to set
maximum output voltage (maxU
out
). MaxU
out
can be set in menu item „output voltage“.
The device requires a minimum pressure to display a value.
Minimum pressure =
2% of the product mesuring range
PRESSURE < 2% measuring range =
Display shows
0 m
3
/h
Minimal flow:
V_min=√(0,02 x measuring range) x k
Maximal flow:
V_max=√(measuring range) x k
HINWEIS
Parameter
Selection or parameter range
Default setting
input temp t1
-30.0...+70.0 °C if t > t1, setpoint is not changed
70.0 °C
input temp t2
-30.0...+70.0 °C if t < t2, setpoint = compensated setpoint
-30.0 °C
comp.
setpoint
setpoint at maximum temperature compensation
differential pressure from 0 % up to 100 % of measuring range
volume flow from 2 % up to 100 % of measuring range, k-factor is
considered
Set 1 = 8888
Set 2 = 8888
Set 1 = 8888
Set 2 = 8888
